Neuramidinase (NA) inhibitor is an anti-flu virus drug that has been developed recently. As a recently developed NA inhibitor, oseltamivir phosphate is effective to type A and B flu virus and has advantages of anti-drug fast, good tolerance of patient and high safety, and is used for the prevention and treatment of flu. oseltamivir phosphate is a therapeutic drug for preventing and controlling pandemic of flu used by World Health Organization and Chinese Ministry of Public Health, and also a drug reserved for national strategy to prevent and control pandemic of flu in China and other countries in the world.
At present, commercial oseltamivir preparation form in China is capsule, its unit dose is 98.5 mg/granule (which contain oseltamivir 75 mg), according to body weight-dose table recommended to children over 1 year old, oseltamivir phosphate is taken in a dose as listed as follows:
Body weightRecommended dose (taken for 5 days)≦15kg30 mg, twice per day>15-23kg45 mg, twice per day>23-40kg60 mg, twice per day>40kg75 mg, twice per day
Clearly, due to large dose, the capsule cannot be exactly administered to Children patients especially lower age children, and thereby the safety of administration cannot be guaranteed; on the other hand, since old people, children and flu gravis patients swallow inconveniently or difficulty, capsule dosage form is not suitable for these special human. Therefore, it is necessary to develop new dosage form of oseltamivir phosphate suitable for old people, children and flu gravis patients.